Editor presentation out of sync with attributes type

I am creating a workitem type (using RTC 2.0.0.2 at the moment) and have defined the attributes I want. Initially I defined a number of attributes as having their type as one the enumerations I created. However, when I came to add the attributes as a presentation on the editor I realised in order to have a multi-select checkbox kind of presentation, I needed the attributes to be defined as a String and then add a property enumeration=<enumeration>.
However, the problem I am experiencing is that having deleted and recreated the attributes in question with the correct type (smallString) - which I can see is right in both the Configuration Data>Work Items>Types and Attributes panel and the Process Configuration Source tab too.
When I go to add that attribute into the editor as a presentation, it doesn't offer me the "Kind" options I would expect from a String type, it acts as if it is still an enumeration type (ie only listing Enumeration, Radio Group, Hidden).

I've tried using the refresh button in the panels as well as Project>Clean.. and closing and restarting the RTC eclipse client but I don't seem able to get the Editor Presentations section to reload whatever it is using as the source of its list of attributes with the latest information.

Any suggestions of what to try gratefully received :?